I've installed kubuntu 7.10 in my ASUS X50N which has a geforce 7000M-graphics-chip. Unfortunately the latest stable driver 100.14.23 isn't supporting this modell, so I tried the new beta-driver 169.04. When I now start my system, I get just a console, and in the /var/log/X.org.0.log there's a message that it can't find a nvidia-GPU. After reloading the nvidia-module and restarting kdm it's working perfect, until the next restart.

According to your bug report, you're sometimes loading the 169.04 kernel module and sometimes loading 1.0-7185. It sounds like you're running into a known bug in the Ubuntu driver packages. Please make sure you've removed all of Ubuntu's NVIDIA driver packages with the --purge option before installing the driver from the .run file. See Ubuntu's documentation for more details.